Metallic piston-ring.



' FIG. 1.

1 e. c. SIEBERTv METALLIC Pl-STON RING.

APPLICATIONUFILED OCT. 12, i916.

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Patented Apr. 17, 1917.

UNITED STATES PATENT OFFICE GEORGE C. SIEBERT, OF CHICAGO, ILLINOIS.

METALLIC IBISTONERING.

'To all whom it concern:

' Be it known that I, GEORGE C. SIEBERT, a

citizen of the United States, and a resident of the city of Chicago, in the county. of (look and State of Illinois, have invented a certain new and useful Improvement in 'Metallic Piston-Rings; and I do hereby declare that the following description of my said invention, taken in connection with the accompanying sheet of drawing, forms a full, clear, and exact specification, which will enable others skilled in the art to which duction of a very, eflicient and serviceable metallic piston ring for steam'engines, gas

engines, intlirnal combustion engines, pumps,

and all other machines in which a piston,

operating in a cylinder, or steam, chest is employe i In piston rings of this nature it is essential that they shall make the piston as nearly fluid tight as it is mechanically possible to make them, and that they shall be expansible to compensate for Wear. I,ac-

. complish these objects by ,the construction disclosed in thedrawings already referred to, and in the'following description of my invention. s

In these drawings, Figure 1 is aplanof an expanded piston ring according to my invention. Fig. 2 is an edge view of a portion of said piston ring. Fig. 3 is a plan of a fragment of said ring. Fig. 4 is a transverse sectional view on line 4t of Fig; 3. Fig; 5 is a like view on line 5-5 of Fig. 3. Fig. 6 is a plan view of a portion of the piston ring, illustrating the same in 'contra'cted condition. Fig. 7 is a fragmentaliview of a, modified construction of my invention. -Fig. 8 is a fragmental view of the 'piston ring, showing its condition after the first step of milling has been performed. thereon. v 7 {It is: evident that metallic piston rings are inadei'n many different sizes, so that for the "purpose *of this disclosure, '1 have illustrated in Fig.1, a piston ring of practically full; sizesuitable for-{the motors of internal 1 Specification 01 Letters Patent.

pointed out in the Patented Apr. 17, 1917 7 Application filed October 12,1916. Serial No. 125,2b0.

combustion engines, especially for those em- 4 -ployed in automobiles, launches, etc. This ring is first produced oversize as anendless I band. It is then split transversely, and'then the joints are formed therein, which, ,when

the ring is contracted, will overlap, or inter connect, and then the ring is contracted and in this condltion ground to exact external size to fitthe cylinder in which it is to be used! The effective qualities of such a ring residein the proper construction of the joint in thering, and this joint I produce in the following manner:

The endless ring heretofore mentioned is 1 clamped in a milling machine and with a suitable milling cutter I split thisring and round off the end of-the portion 12thereof as shown at 13, while at the same time I re-. duce the thickness of the ring'at the end 12 for practically one half of its indicated at 15, and then split this end 1ongitudinally for some distance 'back of said end 12 .to form a slot 14 therein. I then form at the opposing end 16, and in the face of the ring, two grooves 17, 18, thereby leaving between these grooves a tongue 19, which tongue fits into tight sliding fit. The ends of the grooves 17, 1 are rounded, as shown at 20, to correspond to the curvature 13 at the end of the portion 12, so that when the ring is contracted and in the condition shown in Fig. 6, the joint is perfectly closed and barely visible.

It will now be noticed that thetongue 19 fitsperfectly in the slot 14, and that, there fore, fluid cannot pass past this tongue; nor can it pass through the slot 11, so that under all conditions of use the joint in the ring will bepractically fluid tight until the ring has been .worn to such an extent as to render further use thereof practically, if not entirely impossible.

It is, of course, essential that this joint be made as accurately as possible, and with perfect machinery; and for this purpose I have designed special machines to produce this perfect work. The object of rounding the grooves 17,18, at their terminals is to enable thesegrooves'being readily formed with so-called milling tools or cutters; and

thickness, as

the slot 14 by a,

but a trifle more than the usual metallic piston'ri'ng having a diagonal or similar split or'joint, while practical use has demonstrated the fact that my piston ring is far superior to any of the various rings now employed in engines-0i the type described,

and with which I am acquainted.

This packing ring is admirably adapted for use in pumps, used in pumping hot fluids, in steam engine valve chests having piston va1ves,and ir'or many other purposes. :In piston rings for larger engines than those usually employed in automobiles and similar vehicles, I may find it desirable to increase the numberof tongues and slots;- and in Fig. 7, I have illustrated a fragment of a piston ring in side view, which piston ring is supplied with two tongues and coact- King slots. It is, however, evident that the number of tongues and coacting slots may be further augmented without departing from the scope of myinvention and that the method of manufacturing such rings is precisely the same as that heretofore described, the only difference being that a suitable number of milling cutters mounted on a mandrel common to all the cutters are em ployed to produce the slots and tongues heretofore described.

I have heretofore stated that thesecond milling operation on the piston ring consists in splitting the ring to produce the slot 1 L therein, and that the third operation is to mill the grooves 17, 18, in the opposite end of the ring, but it is obviousthat the order of procedure regarding these two operations may be reversed without departing from the scope of my invention.

Having thus fully described this invention, I claim as new, and desire to secure to myself by Letters Patentof the United States I The method of manufacturing metallic piston rings, consisting in first producing an endless ring of larger diameter than the required finished ring, then splitting this ring crosswise and reducing the thickness of one end of said ring for some distance from said "end, at the same time rounding this end, then splitting the ring at one end in the II11(1 die to form a slot therein, then milling grooves at the other-end of said ring and leaving tlie'ends of said grooves rounded to atiord a tongue adapted to enter said slot, then contracting the ring, and finally reducing said ring to operative external size by grinding.

In testimony that I claim the foregoing as my invention, I have hereunto set my hand. GEORGE C. SIEBERT. 

